hasOwnProperty is not a function

[lucianobosco]

Since last update I'm getting hasOwnProperty is not a function
I used to create a payload with differences to be sent to my API through axios:

      const diffs = diff(originalResource.value, resource.value)
      const payload = {
        ...(diffs.hasOwnProperty('name') && { name: resource.value.name }),
        ...(diffs.hasOwnProperty('slug') && { slug: resource.value.slug }),
        ...(diffs.hasOwnProperty('visible') && { visible: resource.value.visible }),
        ...(diffs.hasOwnProperty('postCategory') && { post_category_id: resource.value.postCategory?.id || null }),
        ...(diffs.hasOwnProperty('parent') && { parent_id: resource.value.parent?.id || null })
      }

Did anything change in regards to returned response from method diff(). In that case, how can I get diff() properties changed in order to create a new payload object?

[mattphillips]

Hi @lucianobosco due to a potential vulnerability with unsafely setting the diffed properties on the returned diff object, the diffed object is now created using Object.create(null). This means that the returned diffed object has no prototype and so hasOwnProperty will be undefined.

In your case you could spread the diff object into another object with the default prototype functions available.

      const diffs = diff(originalResource.value, resource.value)
      const d = { ...diffs }
      const payload = {
        ...(d.hasOwnProperty('name') && { name: resource.value.name }),
        ...(d.hasOwnProperty('slug') && { slug: resource.value.slug }),
        ...(d.hasOwnProperty('visible') && { visible: resource.value.visible }),
        ...(d.hasOwnProperty('postCategory') && { post_category_id: resource.value.postCategory?.id || null }),
        ...(d.hasOwnProperty('parent') && { parent_id: resource.value.parent?.id || null })
      }

[lucianobosco]

Hi @lucianobosco due to a potential vulnerability with unsafely setting the diffed properties on the returned diff object, the diffed object is now created using Object.create(null). This means that the returned diffed object has no prototype and so hasOwnProperty will be undefined.

In your case you could spread the diff object into another object with the default prototype functions available.

      const diffs = diff(originalResource.value, resource.value)
      const d = { ...diffs }
      const payload = {
        ...(d.hasOwnProperty('name') && { name: resource.value.name }),
        ...(d.hasOwnProperty('slug') && { slug: resource.value.slug }),
        ...(d.hasOwnProperty('visible') && { visible: resource.value.visible }),
        ...(d.hasOwnProperty('postCategory') && { post_category_id: resource.value.postCategory?.id || null }),
        ...(d.hasOwnProperty('parent') && { parent_id: resource.value.parent?.id || null })
      }

Thanks a lot! That works

[JuanJo4]

Note that inner objects doesn't have prototype too, so even if you spread the object you might face the same hasOwnProperty is not a function error.

const diffs = diff(originalResource.value, resource.value)
const d = { ...diffs }

d.innerObj.hasOwnProperty('myProp') // will throw hasOwnProperty is not a function

A different solution than spreading the diff object could be to use Object.hasOwnProperty.call directly, like this:

Object.hasOwnProperty.call(diffs, prop)